1. Field of the Invention
The present invention relates to an imaging device, an imaging device body, and a lens barrel that include an apodization filter.
2. Description of the Related Art
There is known an imaging device that includes an apodization filter (hereinafter, referred to as an APD filter) having optical characteristics in which light transmittance is reduced as a distance from an optical axis is increased (see JP2005-062733A). The APD filter reduces the amount of light around only a blurred image (spotlight blurring or the like), which is out of focus, without reducing the amount of light around an image plane. Accordingly, the APD filter realizes a beautiful blur by applying gradation to the profile of a blurred image. In JP2005-062733A, the APD filter can be inserted/retreated onto/from the optical axis and the insertion/retreat of the APD filter is performed in accordance with an imaging mode.
Further, an imaging device, which blurs the background by image processing, is known among imaging devices, such as a digital camera that has a short actual focal distance and cannot optically blur the background of a major subject or principal object (see JP2007-124279A). Specifically, in JP2007-124279A, information about distances to a plurality of subjects of an imaging region is acquired during an auto-focusing operation and blurring is electronically applied to subjects other than a major subject in accordance with the distances.
However, the APD filter makes the profile of an optically blurred image be smooth by reducing light. Accordingly, in the event that the APD filter is inserted onto the optical axis in accordance with an imaging mode as disclosed in JP2005-062733A, light is reduced by the APD filter even though a blurred image is not present in the background and the foreground. For this reason, there is a problem in that the brightness of a photographed image is wastefully reduced. Accordingly, it is desired that the APD filter is inserted only in a case in which a blurred image is present.
Since the imaging device disclosed in JP2007-124279A premises an optical system in which an optically blurred image is not generated, the imaging device cannot determine whether or not an optically blurred image is generated.